Froth flotation with secondary-alkyl primary amines



Oct. 8, 1968 FROTH FLOTATION WITH SECONDARY-ALKYL PRIMARY AMINES Filed May 7, 1965 INSOL IN CONCENTRATE INSOL IN CONCENTRATE c. RAY ET AL 3,404,777

2 Sheets-Sheet 2 FE RECOVERY FEQE so 10 so so 40 FE RECOVERY INVENTORS CHARLES LQRAY ROBERT E. BAARSON EDWARD W. LONG ATTORNEY United States Patent 3,404,777 FROTH FLOTATION WITH SECONDARY-ALKYL PRIMARY AMINES Charles L. Ray, Wheaton, Robert E. Baarson, La Grange, and Edward W. Long, Mokena, Ill., assignors to Armour and Company, Chicago, 11]., a corporation of Delaware Filed May 7, 1965, Ser. No. 454,155 5 Claims. (Cl. 209-166) ABSTRACT OF THE DISCLOSURE Secondary-alkyl primary amines of a specific configuration and chain length, alone or in admixture with heterocyclic nitrogen compounds derived from gilsonite, are used as froth flotation collectors.

' tion processes and is useful wherever amines are used as collectors, it has particular applicability to iron ore and phosphate ore flotation.

In iron ore or magnetic iron ore recovery from mixtures of oxidic iron minerals, it is the undesirable silica and miscellaneous cherts and siliceous minerals that are floated away. The desired ore remains behind.

Prior to flotation, the ore is ground, pulped in water, and sometimes, depending on the nature of the ore being treated, preconditioned with starch or dextrin, which is a depressant for the desired iron portion of the ore. It is generally preferred not to use a depressant. Then, a small amount of an amine collector which is preferably readily water-dispersible, and a frothing agent, is added, and the pulp subjected to flotation. The silica rich froth is floated away from the desired iron mineral residue, in one and generally several steps.

In phosphate flotation, one or more steps are used dependent upon the ore being treated. In the two step process, the ore is washed, deslimed, and then conditioned with caustic soda, and a hydrocarbon, such as fuel oil or kerosene. A fatty acid collector, such as tall oil, is then added and the mixture subjected to a first flotation. Phosphate product is obtained as a rougher concentrate. This concentrate is then deoiled or freed of reagents by scrubbing with mineral acid. It is again deslimed in preparation for a second flotation step.

The second step involves flotation of the deoiled, deslimed rougher concentrate with a cationic amine collector. Here, the undesired silica is floated away from the phosphate mineral and is discarded. The underflow, or unfloated portion of the ore remains as the desired phosphate product.

In the one step process, such as presently practiced in treating western phosphate ore, only a fatty acid collector, tall oil, is used to float rougher concentrate which is then upgraded by reflotation. However, no additional collector chemical need be used. The undesired silica and other nonphosphate minerals drop out and report in the underflow which is either discarded or recycled.

Considerable effort has and is being expended to devise more efficient and more economical methods of operation, the objective, in all instances, being to make as complete a separation as possible and to produce a higher grade concentrate with minimum loss of desired mineral, while consuming as little of the relatively costly amine collector as possible.

An object of this invention is to provide a novel amine collector for froth flotation.

Another object is to provide a novel collector mixture which, per unit amount, is even more efficient than said novel amine collector.

Still another object is to provide a more eflicient iron ore flotation process.

Another object is to provide a more etficient phosphate flotation process.

Other objects will in part be obvious and will in part appear hereinafter.

It has now been found that the use of certain specific secondary-alkyl primary amines, alone (that is, as singular compounds or in admixture with similar secondaryalkyl primary amines), or preferably in combination with crude mixed heterocyclic nitrogen material derived from the minearl gilsonite, effects a marked improvement in mineral separation. These secondary-alkyl primary amines, may be represented by the formula:

.FORMULA I R(CHR)xCH(CH2)yH I IHz wherein Typical secondary-alkyl primary amines falling within the above formula are sec-undecylamine, sec-dodecylamine, sec-tridecylamine, sec-tetradecylamine, sec-pentadecylamine, .sec-hexadecylamine, sec-heptadecylamine, sec-octadecylamine and all the isomeric versions thereof as well as mixtures of sec-alkyl primary amines and their isomeric forms such as would be derived from various unsaturated hydrocarbons including but not limited to the mixed C6 to C7, the C7 to C the C9 to C11, the Cu to C15, the C20 to C48, the C9 to cm, the Cu to C14, the C to C C to C sec-alkylamines.

Specific l-methylalkylamines found useful are l-methyloctylamine, l-methyldecylamine, l-methyldodecylamine, l-rnethyltetradecylamine, l-methylhexadecylamine, and l-methyloctadecylamine.

The amine is usually partially or wholly neutralized by a mineral or organic acid such as hydrochloric acid or acetic acid. Such neutralization facilitates dispersibility in water. In the alternative, the amine may be used as is or by dissolving it in a volume of a suitable organic solvent such as kerosene, pine oil, alcohol, and the like hefore use. It should be noted that these solvents sometimes have undesirable effects in flotation such as reducing flotation selectivity or producing uncontrollable frothing.

The concentration of amine used is about 0.01 pound to about 2.0 pounds per ton of ore, the preferred range in most instances being about 0.05 pound to about 1.0 pound per ton.

The gilsonite material referred to occurs as a byproduct in the manufacture of petroleum products from the aforementioned mineral gilsoniteby The American Gilsonite Company. It has been described as containing predominantly mixed alkylated pyridines, pyyroles, indoles, and quinolines, with some of the substituent carbon chains being olefinic. It also contains some unidentified nonnitrogeneous material. However, it is believed to be an inordinately complex mixture of chemical structures. Well over one-hundred different compounds are indicated as being present in the mixture, based on gas chromatographic procedures. The extreme complexity of such a mixture of materials renders a complete qualitative analysis almost prohibitive.

Utilization of all crude, Semipurified or purified byproducts and having a boiling point of greater than about 200 F. resulting from the refining of gilsonite, are utilizable with the amine. Naturally, the composition of such mixed heterocyclic nitrogenous byproducts will vary with the composition of the original gilsonite, the point in the refining process from which they are extracted, the boiling range in which they are extracted and the like. The invention herein described presupposes utilization of all such mixed heterocyclic nitrogenous compounds either in crude or in purified forms. The preferred mixed heterocyclic nitrogen compounds in the practice of this invention are those which have a booiling range of about 200 F. to about 750 F. and particularly those which have an average boiling point within the range of about 450 to about 750 F.

The American Gilsonite Company has assigned descriptive nomenclature to various fractions of this type material as follows.

(1) Light bases from HBF: Extracted from a naphtha stream of approximately 283 F. volumetric average boiling point and 222 F.400 F. boiling range.

(2) Intermediate bases from PFB-Extracted from a heavy naphtha stream of approximately 422 F. volumetric boiling point and 400 F. to 590 F. boiling range.

(3) Medium bases from LGOExtracted from a gas-oil stream of about 520 F. volumetric average boiling point and 460 F. to 665 F. boiling range.

(4) Semipurified acid extracted nitrogen compounds:

(a) Nitrogen 'bases IBoiling range 491 F. to

509 F. at 760 mm.

(b) Nitrogen bases IIBoiling range 610 F. to

641 F. at 760 mm.

(c) Nitrogen compounds III-Boiling range 700 F.

to 710 F. at 760 mm.

(d) Nitrogen compounds IV-Boiling range 745 F.

to 755 F. at 760 mm.

(c) Bottoms VBoiling range 755 F. and higher at 760 mm.

(5) Nitrogen distillate: A crude mixture of nitrogen bases obtained by distillation and representative of 4(a) through 4(c) inclusive as above, plus some nonnitrogenous compounds.

(6) Nitrogen bases concentrate oil: An extracted mixture of cyclic tertiary amines plus some nonbasic nitrogen compounds.

(7) Pyrrole polymer oil-An extracted mixture containing predominantly nonbasic nitrogen compounds and some cyclic basic nitrogen compounds.

In all reference to gilsonite, gilsonite material, heterocyclic nitrogen compound, nitrogen bases concentrate oil and the like herein, use of any, some or all of the various fractions above is intended. All are operable, al though some may have more effectiveness for particular uses.

The preferred amount of gilsonite material utilized should be approximately about 0.01 pound to about 2.0 pounds per ton of ore, the preferred range in most instances being about 0.05 pound to about 1.0 pound per ton, the exact amount varying from ore to ore. It is well known that the character of any ore governs the amounts of flotation reagents utilized in order to provide best results.

The gilsonite material may be applied to flotation pulp in several ways. First, since it usually occurs as a freefiowing liquid at low temperatures, it may be separately added to the pulp at the same time that the amine collector is added. In the preferred way, however, the gilsonite material is first blended with the amine collector and then a sufficient amount of acetic acid or hydrochloric acid is added to neutralize the primary amine collector to the desired degree, followed by dissolving or dispersing the blend to a suitable concentration in makeup water prior to addition to the pulp. An even more preferred way is to disperse a blend of gilsonite material and amine collector in warm makeup water, followed by addition to the makeup water of enough acetic or hydrochlorice acid to solubilize or disperse the blend prior to addition to the pulp. In still another way, a blend of amine collector and gilsonite material is prepared, in such a ratio that the blend exists as a free-flowing liquid with a low freezing point, the gilsonite material acting as a liquifying agent for the primary amine collector which usually occurs as a paste or crystalline solid without considerable heating to melt the amine. In such a form, the gilsonite material and amine are added as a liquid blend, with very little or no heating, directly to the flotation pulp without the undesirable necessity for prior solubilizing or dispersing the amine collector in makeup water.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others thereof, and a composition of matter possessing the characteristics, properties, and the relation of components which will be exemplified in the composition hereinafter described, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the drawings and the following detailed examples which refer to the figures in the drawings:

Example I In this flotation, the effectiveness of a mixture of secalkyl primary amines, as compared to a mixture of normal alkyl primary amines as collectors for coarse phosphate ore separation, was determined. The alkyl group, in each instance, varied from C to C in carbon length. Special attention was given to the amines ability to float the +28 mesh silica selectively.

The ore utilized analyzed as follows:

TABLE I.ORE ANALYSIS Screening Chemical Analysis Weight Assay, Percent Units Distribution, Percent Tyler Mesh Gms. Percent Insol. BPL Insol. BPL Insol. BPL

Sub-Totals --28 Mesh 250.4 49.80 66.79 25.84 33.26 12.87 77.22 28.62

Grand Totals 520.9 100.01 43.07 44.96 100.01 99.99

1 Insolubles.

As is evident, the sec-alkyl primary amine collector s, and alone or in admixture with a nitrogen distillate provides a e at 1600 r.p.m. as substantially better selectivity of bone phosphate lime (BPL) providing equal grade and improved recovery of Amine Collector Flotation (lbs/ton) Time Percent Name Amount in Solids Min.

TABLE II Conditioned Reagents l (lbs/ton) Time in Pine 011 Kerosene 2 Min.

The ore was washed once, allowed to settle for 30 seconds, then deslimed and conditioned at 70% solid Sample No.

then floated in a Fagergren machin follows:

7 9 9 1 091 0 712 0 253 0 9 7 n m m m lfim 9 m 0 0 973 4 0 324 0 0 8 0 L0 7 0 2 9. LOW O 0 2 0 7 0 297 0 5 00% Q 5 6 om 0 83 B 36 m 3 m w 9 m m 36 m 26 m m 215 m 215 m N N N N N N N N N N N N N N N in n N N 0 n N 0 m N N m N N m N N N e N N N n N N s N N b m 1 r. 4 8 2 2 7 .H W N N 3 N N 4. N N 5 N N N 5 N N N 5 N N s 1 a 1 N n n D N N N N N N N N N N N n 7 7 .7 7 7 N N m N W m3 8 4 N 2 2m 6 .2 5 3 5 -3 -1 1 N N N N N N 2 N N 2 N N m N N s t 7 5 64 2 9 032 5 733 W n wfim W%% W %%m 6 w nm W 8% WNW W56 5 mafia 0 899 6 477 5 0.04 B mm M mw M B% M HM. Q .3% M H% Q 1% 4 m 4 1 2 4 1 2 0 WO m 0 1 30 2 850 3 6 4 444 2 069 M W %%M m mwm M EN 0 2% mm 72% 3 WM 731 2 9@@ 1 836 no t 4 4 27.4 45.4 m v. m b 0 W0 M m W 3 6 M M 0 4 4 8 M 3 Z 3 '1 s mwwmmmmmmm m M 0 N N N N N N N N t. n 1 07 01 53 152 563 w W m %%B m fioflw N WW m 22% m N81 N N 753 N 92M 33M 000 0 0 m n ma N me N 0 N wm N .0.0 N mm N .0.0 N new N new 247 000 00 I N .m m N N N N N N N N N 1111111111 T n n n u u n n n n n a 01 t 0 D 5 5 6 009 7 0 m u we N ew N wee N new N nww N mew N an... N 52 N 775 N 705 1 TS ZnTL mwssvwmo c 0 n 05 Man N m N u N wmn N W N wan N mun N men N wen N 041 7199994434 m W I P 21 N N N N N N U N 0111201 1 .m E C h L 1 1 4 0 7 621 9 820 0 154. 0 37 m C H W mmou% m m% m 0 7--H= u 8 H 0 %6% W 180 9 117 0 108 0 261 1 C 0 O y T 4.5 0 25 0 783 0 882 0 73 0 51 0 883 9 7 7 m 4.1 O 13 n .H w T m J 24 m m 314 m 314 m 14 m 32 m 314 9 4 3 1 3 1 1 S p g 0 .w m .1 e 3.3. M 0 w 932 4 96 3 468 8 272 1 1 7 7 4 96 9 34.0 7 424 0 61 A 1 V C 8 9 3 3 8 58 0 034 8 558 8 816 0 7. 2 L S 814 4. 7 0 819 32 9 36 6 0 5 8 w mmw m m mum a mum m m m m m 0 m n 0. nmm m m n m 2m 0 w n 5 2 1 0 8 G e u u r U C Ofl. S .C O0 C im h r. n 5 n m o s N N N N N N N N N N N N N N N N mwmlem w N N N N N N N N N N N N n5.500.000.5570 mw wm 1 N N N N N N N N N N N N N N N N N N N 1242 222 rflm w m N N N N N u u N N N N e et e \1 \l \I M MM G 86 0b.. ame g 0 g 6 M 0 m ee W 8 W BB 6 w w s mum n man m m 0 n 5 um 10 0 new new W a t .1 1 1 .1 1 I I .1 I i 1 I I! D E A. 0 an 8 h. MUM a t m t a t a t a a tt e e t n nn nn T 5 5 m? r 0 @mm mi. @mm a m m 0. 5 o m w 1111111111 0V e m t t tun t tHH tun tun .m n W m m W P M00 M M00 M00 00 M00 M00 M00 M00 0 .w mum s CG ECG CG OG 00 00 00 00 00 00 t t wu 0 55.0. 0 a m 0mm 0mm 0mm 0mm 0mm S S 86 e6 e8 80 e h h 0005555555 mm w e @MM WNMM @MM @MM MM @MM @MM @MM 5MM MM 5552222222 wwppma r man w mew mew mew men men man man one .1 22 w mmmm R R R R RN+ R R R R R .mmmmnc fi n u n n n n n v 1 6 a N N N N N N N 00 mm t 0 N N N N N N N N t ey20 O N 6 a nu N N w e N h 6 1 N N N N 5 0 in p N N N c h hhre a w m N N N N N N NNNNNNNT T m N N N N N N N N N N 1234.0 4 01 0 1 2 3 4 5 11MM%M 1 2 3 4 5 1 1 3 3 3 coarser phosphate ore (that retained on the 28 or lesser mesh screen) than the standard collector-tallow amine.

FIG. I summarizes the above data in a very succinct manner.

Amount TABLE lv continucd ConditionReagcnts 1 Amino Collector (lbs/ton) Pine Oil Kerosene 2 Name Test No.

7 Example II Another phosphate ore sample was floated but this time with special attention given to the influence of chain length of the amine collector.

As is evident from the data above, the sec-alkyl primary amine collectors of this invention, especially when admixed with nitrogen distillate as derived from gilsonite, elfect a better iron separation when compared to the coconut amine. Also, more of the desired iron fraction is recovered on an overall basis. FIG. III illustrates this in a most dramatic way. It will be noted that the selectivity curves for the collectors of this invention are substantially better, than the amine collectors of the prior art. It is also to be noted that the sec-alkyl Example III 10 pnmary amine collectors may be apphed in an un- Noflmagnetlc tacomte Ore illematlte, goethlte, -)4 neutralized as received form while still providing chemically analyzed as contamlng 39% Fe and 38.8% superior results insolubles, has the following screen analysis as indicated Example IV 2 in Table VI:

TABLE VI Another iron ore flotation test series was run, but th1s 0 Hi time on a magnetite ore (magnetic concentrate) using umu 9. ve size wtpemerm Percent Fe the following chain lengths of sec alkyl primary ammes Wt. percent Percent Fe as the collector: 3 6 1 13 33.2 C sec-alkylamiens es .1 29.0 +270 Mesh 3.4 26.3 4.5 27.3 SeC'aIkYIamHFeS +325 14511. 3 33.4 31.2 C sec-alkylamlnes S 125 m igfi 7. 6 33.8 (311-15 sec'alkylamllles +161VI101'011 30.3 39.7 69.4 33.3 C1145 sec-alkylammes admixed with nltrogen distillate +9 Microns. 26. 9 96. 3 (2 1) -9 Microns. 8. 7 100. 0

C sec-alkylammes The Ore was pulped precondltloned and floated through The ore utilized was a natural ma netic concentrat three stages (or four, as noted) of rougher concentrate g e as follows W1th an average calculated head assay of 8.63% msolubles and 64.63% Fe.

TABLE VII Stage additions of the collectors are utilized with 3 to Stage Cenditiim (Float) Lbs./Ton Collector 4 rougher floats as follows:

H1111. mm. F h T bl I TABLE IX 1st rot 2 2 See 3 eV II. Sta

ge Condition Float Lbs/Ton Frother 2nd Fmthu 2 111111.) (min.) COlleOlZOl (M1130)1 3rd Froth M 2 Do. 4th FrOth it any)... 2 D0. 1st FIOth x 4 See Table .03

2nd Froth M 4 d Flotation machine-Wemco at 1,600 r.p.m. 3rd Froth. M 4 glgltation ptH-ggy dlh 4th Froth M 4 D @1151 2 0 Methylisobutylcarbinol. Frther*0561b'/tn Pme Flotation machine-Denver at 1800 r.p.m.

Flotation pH-8.00.1. The results were as follows. Pulp Density-20% Solids,

TABLE VIII Collector Assay of Product Distribution Test Percent Metallurgical Name Amount Gm. Percent Acid Percent Uni Percent Percent Weight Weight Insol. Fe Iusol. Fe

Insol. Fe

33.53 76.21 14 14 25.55 4.74 11.95 13.03 43.26 33 62 3.70 6. 15.23 17.14 14.39 57 32 2.47 9 24.77 Concentrate 31.30 3.30 60 1. 03 19 47. 99

16 1st Froth SC11 15A/ND 4 .112 220.0 22.07 30.14 12.27 2.71 6.39 2nd FIOflL SC11 15A/ND .112 215.3 21.64 64.44 22.75 4. 12.50 3rd Froth sCuns /ND .112 143.5 14. 39 31.05 45.27 6. 16.54 4th FI0th sC1 A/ND .112 125.1 12.55 9.90 53.35 7. 18.60 Concentrate sC A/ND 292.6 29.35 3.15 61.00 17. 45.43

17 1st Froth 50114511 4 .1133 256.3 25.75 79.03 3. 3.33 2nd F10th 30114511 .1188 217.7 21.33 60.23 5. 13.90 3rd Froth-- SC11 15A. .1133 111.3 11.16 22.52 5. .23 Concentrate SC11 15A 4 411.3 41.25 5.34 24. 63.49

1 Coconut oil amine 40% neutralized with acetic acid and added as a 5% active solution.

2 Coconut oil amine-nitrogen distillate mixture (3 to 1) 40% neutrallzed with acetic acid and added as a 5% active solution.

3 Secalkylamine wherein alkyl group comprises mixture of 011 to C15 calrbtqns 100% neutralized with acetic acid and added as a 5% active so u 1011.

4 Sec-alkylamine wherin alkyl group comprises mixture of Cu to C15 carbons-nitrogen distillate mixture (3 to 1) 100% neutralized with acetic acid and added as is to the float suspension. 5

5 Sec-alkylamine wherein alkyl group comprlses mixture of Cu to C15 carbons added as is to the float suspension.

Distribution Percent Fe TABLE X Collector Assay of Product Percent Metallurgical Units Name LbJTon Gm. Percent Acid Percent Amount Weight Weight Insol Fe Insol.

1 1 The results were as follows:

Test

Sue footnotes at end of table.

TABLE XII-Continued Collector Assay of Product Distribution Test Percent Metalurgical Units Name Lbs/Ton Gm. Percent Acid Percent Percent Amount Weight Weight Insol. Fe Insol. Fe Fe 1 All collectors used are sec-alkylamines, the carbon length of the alkyl group indicated by the subscript of the 0 number. Each was added in Ithe amount indicated at each froth as is without neutralization.

The sec-dodecyl primary amine used comprised a. mixture of the following isomers:

2-aminododecane, 27.4% 3-aminododecane, 22.7 4-aminododecane, 2 2.7% aminododecane, 27.2%

The above test results are portrayed graphically in The 11 1s yl primary amine (sC A) produces FIG. V. As seen, the C sec-alkyl primary amine is the a higher percent Fe concentrate and higher recover of best of the group covered by thi in i iron. The gilsonite material improves the recovery even Example VI further and lowers the amount of amine required to do so.

25 In summary, the above data and graphs venfy the In still another magnetite ore flotation test series superiority of the sec-alkyl primary amines wherein the (magnetic concentrate) to determine elfectiveness in cold alkyl group ranges from C to C and especially when pulp (about 40 F.) which is the usual environment in admixed with a nitrogen distillate derived from gilsonite, iron ore country, such as Minnesota, 2. C1145 sec-alkyl for froth flotation processes. They have better selectivity primary amine is compared to an amine blended with a of bone phosphate lime, even if the ore is coarse. They nitrogen base concentrate oil, a standard flotation collecprovide a cleaner separation in uncontaminated form of tor for iron recovery sold to the trade by Armour and phosphate ore. In iron ore recovery, they also have better Company, Chicago, Ill. Usually, collectors are much less selectivity and effect a cleaner iron recovery, even in effective in the cold. cold pulp.

The ore utilized was a natural magnetic concentrate It will thus be seen that the objects set forth above, having an average calculated head assay of 8.53% insoluamong those made apparent from the preceding descripbles and 63.57% Fe. tion, are efliciently attained, and since certain changes The same flotation testing conditons as indicated in may be made in carrying out the above method and com- Table IX above (Example IV) were used. The flotation position of matter without departing from the scope of results were as follows: the invention, it is intended that all matter contained in TABLE XII Collector Assay of Products Distribution Test Temp. Lb./Ton Gm. Percent Percent Percent Metallurgical Units Percent Name Pulp Amount Weight Weight Acid Fe Fe Insol. Insol. Fe

14 1st Froth so -1 A l 3844"- 132 97. 8 19. 44 20. 53 55. O5 3. 99 10. 70 16. 93 2nd Froth 132 106. 9 21. 35 9. 69 62. 21 2. 07 13. 28 21. 01 3rd Froth 0792 57. 1 11. 41 5. 75 65. 34 0. 66 7. 46 11.80 Concentrate 5011-1511. 1 38-44 239. 3 47. 80 3. 82 66. 48 1. 83 31. 78 50. 27

16 1st Froth AB R 40-44- 1 S2. 7 16 49 19. 71 55. 84 3. 25 9. 21 14. 52 2nd Froth 4044 1 131.2 26 17 10. 22 62 01 2. 68 16. 23 25. 59 3rd Froth. 4044 05 102 7 20 48 5. 29 65. 25 1. 08 13. 36 21. 06 Concentrate AB 2 40 184 3 36 86 3. 85 66. 82 1. 42 24. 63 38. 83

1 Sec-alkylamine in which the alkyl group contains 11 to 15 carbon atoms, added as is.f i Blend of coconut oil amine and 5% nitrogen bases concentrate 011 neutralized 100% with acetic acid.

FIG. VI portrays the above results. As noted, the the above description shall be interpreted as illustrative sec-alkylamine of this invention performs considerably and not in a limiting sense. better in cold uplp with respect to percent Fe recover It is also to be understood that the following cla1ms with minimum percent insolublesin the concentrate. are intended to cover all of the generic and specific The following Table XIII numerically summarizes data features of the invention herein described, and all stateso that the improvement can be readily seen: ments of the scope of the invention which, as a matter of language, might be said to fall therebetween. TABLE XIII Now that the invention has been described, what is Grade of claimed 15: Lb co ce Percent 1. A froth flotation process for separating phosphate Ore Damn from its crude ore the imrovement com risin utiliza- T C 11 ctor Lb. Ton Gilsomte Recovery P P g We 0 e I Insol- Fe ofFe non of about .01 to 2 lbs. per ton of ore of an amine n Coconut on ,268 7.36 58.85 61.79 fallmg Wlthm the followlflg formula:

Amine Att. R 11,-011-11 H Imr1 sc ff ifm .356 5.34 60.57 63.49 (C Iron..." sch-15AM... .252

15 wherein R is selected from the group consisting of hydrogen,

an aliphatic radical, a carboxyaliphatic radical, an aminoaliphatic radical, and mixtures thereof,

x and y are positive integers having a sum from 9 to about 47, the total carbon atoms of the compound not exceeding 48.

2. A froth flotation process for separating iron ore concentrates from its crude ore, the improvement comprising utilization of about .01 to 2. lbs. per ton of ore of an amine falling with the following formula:

wherein R is selected from group consisting of hydrogen, an aliphatic radical, a carboxyaliphatic radical, an aminoaliphatic radical, and mixtures thereof, x and y are positive integers having a sum from 9 to about 47, the total carbon atoms of the compound not exceeding 48, as the collector,

3. The process of claim 1 wherein the secondary- 16 alkyl primary amine is a mixture of such amines wherein the alkyl group varies from C to C carbons.

4. The process of claim 2 wherein the secondaryalkyl primary amine is a mixture of such amines wherein the alkyl group varies from C to C carbons.

5. The process of claim 2 wherein the secondary-alkyl primary amine is a mixture of such amines wherein the alkyl group varies from C to C carbons.

References Cited UNITED STATES PATENTS 2,389,875 11/1945 Senkus 260-583 X 2,578,790 12/1951 Duke 209166 2,594,612 4/1952 Bates 2-09167 2,914,174 11/1959 Haseman 209166 3,265,211 8/1966 Ray et al. 209-166 OTHER REFERENCES Chemical Abstracts, vol. 54, 1960, 20713b.

HARRY B.THORNTON, Primary Examiner.

ROBERT HALPER, Assistant Examiner. 

